Tambourgi Denise V, De Sousa Da Silva Marcelo, Billington Stephen J, Gonçalves De Andrade Rute M, Magnoli Fábio C, Songer J Glenn, Van Den Berg Carmen W
Laboratório de Imunoquímica, Instituto Butantan, São Paulo, Brazil.
Immunology. 2002 Sep;107(1):93-101. doi: 10.1046/j.1365-2567.2002.01483.x.
We have recently shown that the sphingomyelinase toxins P1 and P2 from the venom of the spider Loxosceles intermedia induce complement (C)-dependent lysis of autologous erythrocytes by induction of the cleavage of cell surface glycophorins through activation of an endogenous metalloproteinase facilitating the activation of the alternative pathway of C. Phospholipase D (PLD) from Corynebacterium pseudotuberculosis shows some degree of homology with the spider sphingomyelinases and can induce similar clinical symptoms to those observed after spider envenomation. The aim of this study was to investigate if the bacterial PLD-induced haemolysis of human erythrocytes was C dependent and if cleavage of glycophorins occurred. We show here that haemolysis of both PLD- and P1-treated human erythrocytes was C dependent, but while PLD-mediated haemolysis was dependent on activation of the classical pathway of C, P1 induced lysis via both the classical and alternative pathways. P1, but not PLD, induced cleavage of glycophorins and no change in expression of complement regulators was induced by either of the toxins. In both cases, annexin V binding sites were exposed, suggesting that the membrane asymmetry had been disturbed causing exposure of phosphatidylserine to the cell surface. Our results suggest that C susceptibility induced by L. intermedia and C. pseudotuberculosis PLD is a result of exposure of phosphatidylserine, and the higher potency of P1 toxin can be explained by its additional effect of cleavage of glycophorins.
我们最近发现，来自中间洛氏蛛毒液的鞘磷脂酶毒素P1和P2通过激活内源性金属蛋白酶诱导细胞表面糖蛋白的裂解，从而促进补体（C）替代途径的激活，进而诱导自体红细胞的补体依赖性裂解。来自伪结核棒状杆菌的磷脂酶D（PLD）与蜘蛛鞘磷脂酶有一定程度的同源性，并且可诱导出与蜘蛛毒液注入后所观察到的类似临床症状。本研究的目的是调查细菌PLD诱导的人红细胞溶血是否依赖补体，以及糖蛋白是否发生裂解。我们在此表明，PLD和P1处理的人红细胞的溶血均依赖补体，但PLD介导的溶血依赖于补体经典途径的激活，而P1通过经典途径和替代途径诱导细胞裂解。P1可诱导糖蛋白的裂解，但PLD不能，并且两种毒素均未诱导补体调节因子表达的改变。在这两种情况下，膜联蛋白V结合位点均暴露，表明膜不对称性受到干扰，导致磷脂酰丝氨酸暴露于细胞表面。我们的结果表明，中间洛氏蛛和伪结核棒状杆菌PLD诱导的补体敏感性是磷脂酰丝氨酸暴露的结果，P1毒素更高的效力可通过其对糖蛋白裂解的额外作用来解释。
